Plug and face plate



7 July 14, 1959 M. B. MONTGOMERY, JR 2,895,119

PLUG AND FACE PLATE Filed July 5, 1955 Fig. 2

Malcolm 8. Montgomery, J1:

INVENTOR.

all

United States Patent PLUG AND FACE PLATE Malcolm B. Montgomery, Jr., Yazoo City, Miss., as-

signor of one-half to Edmund Warren Montgomery II, Jackson, Miss.

Application July 5, 1955, Serial No. 520,040 6 Claims. Cl. 339-91) This invention relates to the class of electrical connectors and is a continuation-in-part of the application of Malcolm B. Montgomery, Jr., Serial No. 335,344, filed February 5, 1953, and now abandoned, for Receptacle and Plug.

The primary object of the present invention resides in the provision of an electrical connector comprising a plug which is adapted to be utilized in combination with aface plate for an electrical [receptacle or outlet box so as to prevent the possibility of accidental electric shock from faulty connections between the prongs of the plug and the contacts of the receptacle while also providing means for insuring a positive connection between the plug and receptacle.

Further object of the invention resides in the provision of a face plate of novel construction adapted to be utilized' in combination with conventional electrical recep tacles and which can be substituted for conventional face plates in a simple manner.

. Another object of the invention resides in the provision of a novel electrical plug having means for insuring ice 2 is used to generally designate the plug comprising one of the elements of the present invention, the other element being the face plate generally designated by reference numeral 12. The plug 10 includes an outer insulative casing 14 formed of any suitable material and provided with a weight lightening cavity 16 therein which also serves to conserve on material. The electrical conductors indicated at 18 extend through an opening 20 in the outer casing 14.

Formed in the outer casing 14 are a pair of opposed tapered recesses 22 and 24. Seated in these recesses 22 and 24 and held by suitable screws or fasteners 26 and 28 are a pair of resilient retainer hooks 30 and 32 having angulated return end portions 34 and 36 at the outermost ends thereof, the hook extending outwardly beyond the outer casing 14. I

Secured to the outer casing 14 and extending outwardly beyond the outer casing 14 is an inner body 38 of substantially dish-shape having a central cavity 42 therein. Suitable screws or other fasteners, as indicated at 44 and 46, are used to hold the inner body 38 in position. Tapered grooves 48 and 50 aligning with the tapered recesses 22 and 24 are formed in the outer surfaces of the inner body 38 and are adapted to receive the retainer hooks 30 and 32 therein.

By means of fasteners 44 and 46 prongs 56 and 58 are attached to the inner body 38. Fasteners 52 and 54 serve as terminals for connecting the conductors 18 to the prongs 56 and 58. A fiber disk 60 of conventional construction is apertured as at 62 and 64 so that the rongs 56 and 58 can extend therethrough.

against the plug becoming detached from the receptacle while also providing an arrangement of parts whereby the connecting wires cannot be readily pulled from engagement with the contact pron-gs.

The construction of this invention features a plug in which resilient hooks are held in place within tapered recesses in an outer casing. These hooks extend beyond the casing and are adapted to engage within recesses in the 'walls forming the chamber for receiving the inner body member of the plug. The walls on the face plate which form a chamber for receiving an inner body of the plug are perpendicular to the face plate.

Still further objects and features of this invention residein the provision of electrical connectors which are simple in construction, capable of being made from any readily available and desired material such as Bakelite, synthetic plastic resins, glass, rubber, or other suitable insulative materials and which are inexpensive to produce thereby permitting wide distribution and utilization.

These together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this plug and associated face plate, preferred embodiments of which have been illustrated in the accompanying drawings, by way of example only, wherein:

Figure 1 is a perspective view illustrating the plug as seated in one of the chambers of the face plate;

Figure 2 is an enlarged horizontal sectional detail view as taken along the plane of line 22 of Figure 1;

Figure 3 is a perspective view of the plug; and

Figure 4 is an end elevational view of the plug with a portion thereof being broken away to show other parts in section and with the insulative fiber disk removed therefrom.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral 10 The casing 14 is provided with a pair of openings 66 and 68 therethrough through which buttons 70 and 72 attached to the retainer hooks 30 and 32 extend. These buttons 70 and 72 can be pressed to shove the retainer hooks 30 and 32 into the aligned grooves 22 and 24 and recesses 48 and 50 to hold the hooks out of engagement with the face plate 12.

The face plate 12 includes a plate member 78 which has pairs of apertures as at 80 therethrough. Surrounding these pairs of apertures 80 are Walls 82 and 83 which serve to form chambers 84 with the Walls 82 and 83 defining the periphery of the chamber. The wall 82 has the inner surface thereof extending substantially normal to theplate 12. This raised wall 82 which forms the chamber 84 is adapted to receive within the confines thereof the inner body 38 with the book ends 34 and 36 of the retainer hooks 30 and 32 being engaged Within a pair of recesses 88 and 90 opening into the chamber 84 formed by the raised wall 82. The walls 82 and 83 are similar.

The prongs 56 and 58 are adapted to extend through the pair of apertures into the openings 93 in the conventional outlet receptacle 94 positioned behind the face plate 12 and held in place by fastening screw 96 extend ing through a raised portion 98 joining the walls 82 and 83 as is conventionally provided for a face plate.

When it is desired to insert the plug 10 into the receptacle 94, it is merely necessary to insert the inner body 38 and prongs 56 and 58 carried thereby into the chamber 84 and apertures 93. Because the ends 34 and 36 are angulated it is not necessary to depress the buttons 70 and 72 for insulation. Then, the buttons may be released at which time the hook ends 34 and 36 will engage Within the recesses 88 and 90. The plug may be easily withdrawn upon depression of the buttons 70 and 72. However, the retainer hooks 30 and 32 will serve to maintain positive contact of the prongs 56 and 58 while also assuring against accidental disengagement of the plug 10. In addition to this, it is impossible to insert any foreign substance into one or more of the openings in the receptacle when the plug 10 is in position.

- 1.- An electrical connector comprising a casing, op-

posed insulated retainer hooks secured to said casing and extending outwardly beyond said casing, an inner insulative body positioned in said casing .and extending outwardly of said casing, said inner body having grooves therein receiving said hooks, said hooks having end portions projecting laterally of said inner body and prongs carried by said inner body, said casing having tapered recesses therein, said retainer hooks being resilient and being seated in said recesses separated and insulated from said prongs, said casing having openings therein communicating with said recesses, and buttons on said hooks extending through and beyond said openings. 7

2. An electrical connector comprising a casing, opposed insulated retainer hooks secured to said casing and extending outwardly beyond said casing, an inner insulative body positioned in said casing, said inner body extending outwardly of said casing beyond said hooks, said inner body having grooves therein receiving said hooks, said hooks having end portions projecting laterally of said inner body and prongs carried'by said inner body, said casing having tapered recesses therein, said retainer hooks being resilient and being seated in said recesses separated and insulated from said prongs, said casing having openings therein communicating with said recesses, and buttons on said hooks extending through and beyond said openings.

3. An electrical connector comprising a casing, opposed insulated retainer hooks secured to said casing and extending outwardly beyond said casing, an inner insul ative body positioned in said casing, said inner body extending outwardly of said casing beyond said hooks, said inner body having grooves therein receiving said hooks, said hooks having end portions projecting laterally'of said inner body and prongs carried by said inner body, said casing having tapered recesses therein, said retainer hooks being resilient and being seated in said recesses separated and insulated from said prongs, said casing having openings therein communicating with said recesses, and buttons on said hooks extending through and beyond said openings, said grooves being tapjred and terminating before the outermost end of said bo y.

4. A face plate in combination with an electrical .connector, said face plate comprising a plate member having at least one aperture therethrough, a raised wall integrally formed with said plate member and extending about and surrounding said aperture forming a plug receiving chamber having an inner peripheral wall extendingsubstantially normal to said plate member, and a pair of opposed recesses in said wall opening into said chamber, said electrical connector comprising a casing, opposed insulated retainer hooks secured to said casing and extending outwardly beyond said casing and seating in said recesses in said wall, an inner insulative body positioned in said casing and extending outwardly of said casing, said inner casing seating in said chamber,

sesame I I 7 said inner body having grooves therein --hooks, and prongs carried by said inner body extending receiving said through said aperture, said hooks being separated and insulated from said prongs.

5. A face plate in combination with an electrical connector, said face plate comprising a plate member having at least one aperture therethrough, a raised Wall integrally formed with said plate member and extending about and surrounding said aperture forming a plug receiving chamber having an inner peripheral Wall extending substantially normal to said plate member, and a pair of opposed recesses in said wall opening into said chamber, said electrical connector comprising a casing,

. opposed insulated retainer hooks secured to said casing and extending outwardly beyond said casing and seating in said recesses in said Wall, an inner insulative body positioned in said casing and extending outwardly of said casing, said inner casing seating in said chamber, said inner body having grooves therein receiving said hooks, and prongs carried by said inner body extending through said aperture, said hooks being separated and insulated from said prongs, said grooves being tapered and terminatingbefore the outermost end of said body.

- 6. A face plate in combination with an electrical connector, said face plate comprising a plate member having at least one aperture therethrough, a raised wall integrally formed with said plate member and extending about and surrounding said aperture forming a plug receiving chamber having an inner peripheral Wall extending substantially normal to said plate member, and a pair of opposed recesses in said wall opening into said chamber, said electrical connector comprising a casing, opposed insulated retainer hooks secured to said casing and extending outwardly beyond said casing and seating in said recess in said wall, an inner insulative body positioned in said casing and extending outwardly of said casing, said inner casing seating in said chamber, said inner body having grooves therein receiving said hooks, and prongs carried by said inner body extending through said aperture, said hooks being separated and insulated from said prongs, said grooves being tapered and terminating before the outermost end of said body, said casing having tapered recesses therein receiving said retainer hooks, said casing having openings therein communicating with said tapered recesses, said retainer hooks beingresilient and having buttons thereon, said buttons extending through and beyond said openings.

References Cited in the file of this patent UNITED STATES PATENTS 1 ,771,757 Keeper July 29, 1930 1,976,501 James Oct. 9, 1934 2,231,001 Engstrom Feb. 11, 1941 2,240,050 Nuebling Apr. 29, 1941 2,378,105 Roesch June 12, 1945 1 2,406,030 OBrien Aug. 20, 1946 2,430,514 Knausz Nov. 11, 1947 2,498,743 Theriault Feb. 28, 1950 

